MASHPEE — A former New York pediatrician facing federal child pornography charges was the target of two Mashpee police inquiries in late 2012, authorities say.

Mashpee Police Chief Rodney Collins said the department received two complaints about Dr. Daniel J. O'Hern, 64, shortly after O'Hern moved to the Quashnet Valley condo complex. In October 2012, a woman in the condo complex said she repeatedly saw O'Hern walking his dog at all hours of the day and looking at her through her second-story bedroom window. Then in December 2012, a woman said her children, who were at their father's house in the complex, had reported O'Hern was taking pictures of them while they were outside and had, at one point, invited the children inside to pet his dog.

In neither case was there probable cause to file charges, Collins said, and police reports show O'Hern denied any wrongdoing. But in light of O'Hern's June 24 arrest, Collins is asking the public to report any other encounters with O'Hern that, in retrospect, may seem questionable.

"We're more than happy to check into anything that now seems to be of elevated concern to someone," he said Wednesday, speaking at a forum to help parents learn to keep their children safe from sex offenders.

O'Hern, described by authorities as a semi-retired pediatrician, was arrested after federal postal inspectors found dozens of images and videos featuring child porn on his computer as part of an investigation into online trading of the images, court records say.

O'Hern has lived in Mashpee for about two years but does not have a license to practice medicine in Massachusetts, according to state records. His New York medical license has lapsed.

O'Hern is being held at the Plymouth County Correctional Facility pending the outcome of a July 10 federal court hearing, which will determine if probable cause exists for charges against him of possession of child pornography and distribution and attempted distribution of child pornography.

In the wake of the arrest, Wednesday's forum was held at Mashpee Town Hall by Children's Cove, the Cape and Islands' child advocacy center. The forum was sparsely attended — five people came to the 8 a.m. session, two of whom were members of the media. But representatives from the Mashpee and Barnstable police departments still shared advice on signs of a potential abuse situation and how to avoid potentially dangerous situations, especially online.

Leslie Moreland, mental health coordinator for Children's Cove, said some signs of an abuse situation in children can include isolation, change in mood, sudden fear of a particular place or person, sexualized behavior with toys, or sudden bed-wetting.

Kevin Connolly, a Barnstable police detective who works with the Cape Cod Computer Crime Unit, said parents of older children need to be aware of what their kids are doing online, especially on social media networks.

"Children who fall victim to online predators are looking for attention or looking for an adult to talk to," he said.

Connolly added that being "friends" with your children on social media isn't enough — parents need to have their children's passwords and regularly review their accounts to make sure there's no bullying going on or an online predator hasn't been lurking.

"Log in and look at their private messages," he said. "You might not be able to see everything just by being their friend."